More than 3.4 billion people, nearly half the world’s population, own at least one mobile phone in 2013. As of 2010, more than 90 percent of people worldwide were covered by a mobile phone signal.

The number of mobile subscriptions—that is, the number of active accounts that have access to a mobile network—far surpasses the number of phone owners. It grew from 1 billion subscriptions in 2000 to a projected figure of more than 6.8 billion by the end of 2013. This number is higher than the number of people owning phones because many people have multiple mobile devices or use multiple SIM cards in one phone. As a result, the number of mobile subscriptions is expected to surpass the world’s population in early 2014, according to the International Telecommunication Union, an agency of the United Nations.

The annual rate of growth is beginning to slow, however, as markets become increasingly saturated. Annual additions to mobile subscriptions peaked in 2010 at 680 million. The subscription rate began to dip in 2011, and an estimated 424 million new subscriptions will be added in 2013—some 250 million fewer than in 2010.

The developing world is home to nearly 4 billion more active mobile phone subscriptions than the industrial world. This is not surprising, given the distribution of world population. On a per capita basis, however, the picture is far different: on average, industrial countries have 128 subscriptions per 100 people, compared with 89 per 100 people in developing countries. The figure in developing countries is expected to top 100 subscriptions per 100 people in 2014.

The future of the mobile phone industry will be less about adding new subscriptions and more about improving existing service. The most common mobile network in the world uses 2G (second generation) technology that allows users to talk and send text messages. 2G accounts for nearly 4.7 billion mobile subscriptions today. In the developing world, 2G is the dominant mobile platform because the network is very inexpensive to install, costing less than fixed-line networks for wired phones. The ability to set up 2G networks on difficult terrain without much pre-existing infrastructure has led to “leapfrogging,” in which many users skip landline technology altogether in favor of mobile phones.

Perhaps one of the most important side effects of the growing mobile phone industry in the developing world is that financial services have become tethered to mobile phone use in poor regions. Areas with high poverty tend to have mobile subscription rates of 50 out of 100 people, while only 37 percent of people living there have access to a physical bank branch. Financial institutions have begun to leverage the existing infrastructure for mobile phones so that a host of transactions—such as opening a savings account, paying bills, or transferring money—can be conducted at local mobile retail stores.

One of the most dramatic uses of mobile phones was during the Arab Spring protests in 2010. One Egyptian activist explained, “[W]e use Facebook to schedule the protests, Twitter to coordinate, and YouTube to tell the world.” The Dubai School of Government found that 9 out of 10 Egyptian and Tunisian protestors used Facebook to coordinate and popularize their protests. Although most social media sites, such as Facebook, are available via computer, more people in Egypt own phones than computers, and mobile phones were preferred in street protests because they could be carried anywhere and easily concealed.

Although mobile phones open up new avenues in economics and politics, their production and disposal often comes at a very high human cost. Factories in countries like China get contracts from electronics and phone companies to produce the devices as cheaply as possible, and as a result they cut corners in ways that can have severe impacts on workers’ health and entail other severe labor abuses.

Mobile phones also create certain health and environmental problems when they are thrown away or recycled improperly. People in the United States replace their mobile phones once every two years on average. In 2010, over 150 million phones were thrown away or recycled in the country alone. Old phones, along with other so-called e-waste, are often exported to countries like India and China, where the valuable materials contained in them are extracted in ways that endanger the health of the workers and that pollute the local environment with dangerous toxics. Exposure to the phones’ components can have severe neurological effects, especially on the children who are most often the ones involved in this extraction.

Further highlights from the report:

3G and 4G networks now cover over 50 percent of the world population, accounting for approximately 75 subscriptions out of 100 in industrial countries but only 20 subscriptions out of 100 in developing countries.

Estimates indicate that by 2018, there will be 9.3 billion mobile subscriptions (with most of the added growth occurring in developing countries) and that mobile-broadband subscriptions will account for 6.3 billion of those devices—roughly two-thirds of the total market.

Mobile phones present great opportunities for development and aid groups because people read approximately 97 percent of their text messages, compared with only 5–20 percent of their e-mails, making a text message one of the most effective ways to convey important news.